David Lineback, PhD, provides his perspective and expertise on acrylamide in foods and current research underway. Dr. Lineback is a past Director of the Joint Institute for Food Safety and Applied Nutrition at the University of Maryland, College Park, MD.
Some new studies on acrylamide in foods have been published recently. Can you tell us what acrylamide is and why it is an issue?
Acrylamide is an industrial chemical which in known to cause cancer in animals at very high levels of exposure. Acrylamide is not added to foods; however in 2002, researchers at the Swedish National Food Administration and Stockholm University detected it in very small amounts in some baked and fried foods. At that point things began to happen very quickly and organizations around the world began to do additional research to determine the potential of any public health risk, if any, of acrylamide in food.
Why is acrylamide in foods? Is there a difference between the industrial chemical and the acrylamide in my food?
As an industrial chemical, acrylamide is used in the formation of polyacrylamide, which is used in water purification, pulp and paper processing, and a number of other industrial uses. Acrylamide is not added to foods. It forms naturally in plant-based foods, particularly starches, as part of the browning reaction that occurs when we fry, roast, bake or toast them. During the cooking process, sugars present in the food (glucose and fructose) combine with the amino acid asparagine to form acrylamide. While it was not previously identified in foods, it has been present as long as we have been preparing baked and fried foods.
What foods does acrylamide exist in?
Acrylamide is found in a range of foods that undergo frying, roasting, baking, and toasting, whether in a food production plant, in a restaurant, or even at home. Acrylamide is found mainly in foods made from plants, such as potato products, bread products, or coffee. The U.S. FDA provides information regarding acrylamide content in individual food products. See: http://www.cfsan.fda.gov/~dms/acrydata.html#u1004.
Does acrylamide cause cancer? Should I remove certain foods from my diet and stop eating them all together?
No. We currently do not have any solid evidence that acrylamide causes cancer in humans in the amounts that exist in foods. There have been several animal studies that indicate acrylamide can be carcinogenetic at very high levels; therefore it has been listed as a probable carcinogen in humans. However, human data is not been sufficient to show this. Several global health organizations and scientists around the world are continuing to conduct research to determine any potential link between acrylamide from foods and cancer risk. Based on the current research and available data, it is extremely difficult to recommend avoiding certain foods to reduce the risk of cancer. I and most experts would recommend eating a balanced diet, which would keep fried foods in moderation.
We don’t yet know that reducing acrylamide in foods will reduce the risk of cancers. If you are particularly concerned about cancer, the FDA has resources that list the acrylamide contents of many foods. In particular you could consume in moderation coffee, French fries, brown-colored potato chips and brown toast as these items will likely be higher in acrylamide. The darkness in some things is related to acrylamide levels as it is formed in the browning process. Many of these foods that are suggested in moderation anyway and have been consumed for many years. They should continue to be eaten in moderation
If we don’t know it causes cancer why is there so much discussion surrounding it?
Currently there is limited human data on acrylamide exposure from foods. Many countries have established these values for their population from a review of their diets. Toxicological research has been done mostly in rodents, which exposed them to levels 1,000 to 10,000 times the acrylamide found in foods. This is the normal approach for such toxicological studies. It is very difficult to determine the effect, if any, of the levels of acrylamide in food through these models, as the animals would have to consume a very large amount of food to produce observable effects. Scientists are also working through epidemiological studies to determine any potential risk of the consumption of acrylamide and increased risks of cancers. These studies use a cohort and ask participants questions about the frequency (food frequency questionnaire), of consumption of acrylamide-containing foods, looking at the foods they have eaten and whether people who have consumed certain foods have an increased risk for some cancers. These studies also present a problem as most cohorts are not large enough to have the statistical power to determine the small increases in risk levels that acrylamide may pose. In conducting these studies to date on acrylamide, most do not show any increased risk of most cancers.
What additional research is coming?
There is still a great deal of emerging research on this topic. Three to four major reports will be coming out soon; including a Draft Risk Assessment from Health Canada which will be used to establish a management plan for acrylamide in that country. In the U.S., The National Center for Toxicological Research (NCTR) report is of particular interest to the scientific community. They will attempt is to use a model developed for comparing rodents exposed to low levels of acrylamide to people to determine whether consumption of foods containing acrylamide are associated with an increased risk of cancer. Even when this study is complete, it will be very hard to determine whether acrylamide in food causes cancer. For one, it is very difficult to go from a rodent model to make predictions about a human model and two, just because studies may find there is an increased risk, it does not mean that dietary acrylamide is necessarily the root cause of these cancers.
Additionally, the Joint FAO/WHO Expert Committee on Food Additives (JEFCA) will also provide valuable information regarding acrylamide in foods after they complete their second risk assessment of acrylamide in foods, which is planned for late 2009. These data are important to establishing future management strategies in various parts of the world.
If I could give one piece of advice, when watching the reports come out from highly respected groups, try to take an overall look at them together rather than look at each ones’ findings individually. Overall, you will see that the risk of cancer from acrylamide in foods is extremely low. However, they will provide risk management strategies for countries, food companies and individuals who are concerned about acrylamide in food.
What exactly is industry doing to reduce acrylamide in the food supply?
In Europe, the Confederation of the Food and Drink Industry has been working to determine and reduce levels of acrylamide formed in food during the cooking processes. They have developed the CIAA Acrylamide Toolbox as a central location for all sizes of companies to share information about ways to reduce acrylamide in food processing. Information from U.S. companies is being integrated into a revised Toolbox. Additionally, the food industry is undertaking the following activities:
- The U.S. food industry discovered an enzyme that reduces acrylamide in dough-based products and has shared this technology with others to benefit all consumers;
- The industry has also identified and implemented other measures such as safely reducing cooking temperatures, increasing moisture levels and selecting different (plant) varieties and changing storage temperatures.
Many of these practices and more can be found in the CIAA Acrylamide Toolbox as well as the Draft WHO / FAO CODEX Code of Practicefor the Reduction of Acrylamide in Food.
Despite these resources, it is unlikely we will be able to remove acrylamide from all foods. The methods discussed are not guaranteed to lower acrylamide in all foods or processes, rather it is a trial and error process. Acrylamide is formed from components naturally present in plant-based foods during the heating processes required to make them consumable. Additionally, removing all acrylamide often means changing the cooking process and thus the actual palatability of the product for the consumer. It is highly unlikely that acrylamide can be reduced or removed from many foods without altering their color, texture, flavor, consumer acceptance, and, potentially, their food safety.